SUNNY ISLAND 5048 - Technical Description - Wind & Sun Ltd.
SUNNY ISLAND 5048 - Technical Description - Wind & Sun Ltd.
SUNNY ISLAND 5048 - Technical Description - Wind & Sun Ltd.
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PV Inverters in Stand-alone Grid Systems SMA Solar Technology AG<br />
This function is shown in the following figure:<br />
The different settings have the following meanings:<br />
• fAC = 0 refers to the base frequency of the micro grid created by the <strong>Sun</strong>ny Island.<br />
• fAC Delta‒ and fAC Delta+ refer to the maximum range in which the PV inverter is active relative<br />
to fAC = 0. Fac-delta– and Fac-delta+, for example.<br />
• fAC Start Delta is the frequency increase relative to fAC = 0, at which point the power adjustment<br />
via frequency begins.<br />
• fAC Limit Delta is the frequency increase relative to fAC = 0, at which point the power adjustment<br />
via frequency ends. The power of the PV inverter at this point is 0 W.<br />
If the value is below the fAC Delta– limit or exceeds the fAC Delta+ limit, the PV inverters disconnect<br />
from the grid.<br />
When FSPC is activated and the diesel generator in the stand-alone grid is operating, the diesel<br />
generator determines the frequency, and the PV inverters react to certain changes in the diesel<br />
generator frequency. The diesel generators generally operate at 50 Hz under load. For this reason,<br />
in most cases the PV inverters will deliver their entire power to the stand-alone grid, even when the<br />
generator is running.<br />
If the current battery voltage (V Bat ) is greater than the nominal battery voltage (V Bat, nom )<br />
and is also to be synchronized with an external source (generator), the <strong>Sun</strong>ny Island<br />
temporarily increases the frequency and disconnects the PV inverters using the frequency<br />
shutdown method (overfrequency). Afterwards, it synchronizes with the generator.<br />
144 SI<strong>5048</strong>-TB-TEN110340 <strong>Technical</strong> <strong>Description</strong>